Personal flotation devices, or "PFDs", have evolved over the years from the old "Mae West", or kapok, type of life vests; then to vinyl covered foam rubber life jackets; and, finally, to more specialized flotation devices which are used when one engages in different types of water sports and boating activities. The U.S. Coast Guard has instituted regulations regarding the minimum flotation required of PFDs. As set forth in those regulations, the minimum flotation required depends upon the expected use of the PFD. The U.S. Coast Guard Regulations, Title 33 of the Code of Federal Regulations ("CFR"), Chapter 1, Part 175, Subpart B, require that recreational boats have at least one Coast Guard approved PFD on board for each person on a boat.
In recent years, safety concerns have caused the U.S. Coast Guard to modify the Regulations regarding minimum flotation for PFDs. Accordingly, PFDs are now segregated into different classes which depend upon the type of boating activity in which the PFD is intended to be used. Generally, there are five classes of PFDs as stipulated within the U.S. Coast Guard Regulations. They are designated as Type 1, offshore life jacket; Type 2, near shore buoyant vest; Type 3, flotation aid; Type 4, throwable device; and Type 5, special use device. The Type 3 PFDs, or flotation aids, are generally the best suited for most recreational water sports in which a significant degree of mobility, and arm and shoulder movement, are involved. Accordingly, they tend to be the most common type of PFDs in use. The U.S. Coast Guard Regulations require that all Type 3 PFDs have a minimum of 15.5 pounds of flotation when they are manufactured. As most adults generally weigh between 10 and 12 pounds when submerged in water, i.e., significantly less than the minimum Coast Guard flotation requirement, the provision of at least 15.5 pounds of buoyancy is sufficient to help insure that a person wearing such a PFD, properly fitted, will be able to float.
In the past, increasing the buoyancy of PFDs has generally required that there be an associated increase in the bulk of the PFD, as additional buoyant material is required to increase a PFD's buoyancy. The addition of thicker and/or additional buoyant material to a PFD typically results in increased bulk which tends to inhibit or restrict the freedom of movement of the wearer. This restriction on the freedom of movement of the wearer is especially a problem for PFD wearers who are involved in strenuous water sport activities which require a significant amount of movement of their arms, shoulders, and torso. By way of example, in canoeing, kayaking, rafting, wind surfing, or similar activities, significant arm, shoulder, and upper torso movement is required when the wearer is paddling or maneuvering sails and lines. In addition, most conventional PFDs do not tend to move with the wearer. Instead, they tend to ride up, or shift, on the wearer's torso, thereby making the PFD uncomfortable to wear and also interfering with the wearer's mobility.
As PFDs are more likely to be worn if they are comfortable, and as the mortality rate, due to drowning, would be lower if PFDs were always worn, the provision of a comfortable PFD would assist in decreasing the mortality rate due to drowning. Accordingly, it can be seen that a need has existed for a PFD which flexes with, and conforms more naturally to, arm, shoulder, and torso movement of a wearer, so that as the wearer moves, the PFD moves with the wearer. A PFD which moves with the wearer, rather than shifting, is far less likely to become uncomfortable for the wearer or to interfere with, or restrict, the movements of the wearer. At the same time, it would be desirable for such a PFD to provide enhanced flotation, so that it continues to meet or exceed U.S. Coast Guard Regulations for PFDs. Additionally, the greater comfort afforded by such designs would allow locating fabric laminated flotation sections so as to provide greater protection from impacts of various kinds, both when the wearer is "on board", and in the event of an unplanned swim (as frequently experienced by rafters and kayakers, etc. in rocky rivers.
PFDs are generally constructed of a fabric material which encloses a foam material which is used for flotation. Typically, the fabric material is sewn around the foam material thereby enclosing and protecting the flotation foam in a fabric "pocket". As is well known in the art, the present design of PFDs includes a number of sewn pockets, each of which typically retains a piece of flotation foam. The size and shape of the pockets, and the size and shape of the enclosed foam, must, of course correspond to one another.
As the foam which is typically used in a PFD is firmer than the surrounding fabric material, bending of the PFD can be enhanced by providing a seam between adjacent foam-holding pockets. This is commonly referred to as a "quilting seam". As is well known to those skilled in the art, present and past PFDs of this type exhibit substantial amounts of sewing, and numerous seams, in order to provide its desired shape, while enclosing a sufficient quantity of flotation foam to provide at least the minimum flotation required by the U.S. Coast Guard regulations for the type of PFD being manufactured. In addition, the sewn seams allow for increased bending of the PFD where desired. Even a relatively simple PFD design will generally include at least two side panels, a back panel, and, typically, at least two front panels (which are usually joined together by some sort of closure system, such as straps or a zipper, when the PFD is worn). Thus, even a simple design for a PFD may include five pockets, each of which encloses a piece of flotation foam which has been cut to the desired shape prior to being inserted into the pocket which is formed in the fabric material to receive the flotation foam.
If more complicated designs are desired, for example, to provide for more conformal bending of the PFD, then it is necessary to include additional seams where such additional bending is desired, as the seams act as the "hinges" between adjacent panels. As quilting seams are added, there is the obvious loss of space within the empty fabric envelope, which translates into less space available for the flotation material itself, and, therefore, reduced flotation and buoyancy of the PFD. Of course, using current manufacturing techniques and materials, this means that there must be additional pieces of foam, and/or pieces of additional thickness, as well as additional sewn seams, all adding to the complexity of the design, the number of seams required, and the labor and material costs associated with manufacturing the PFD.
While those skilled in the art will recognize that "belts", vests, rafts, and some other flotation articles have been made for some time by dipping a flexible flotation foam into a liquid vinyl, so that the vinyl forms a skin over the foam, the use of such technology has generally been limited to providing flotation devices (belts and vests) for use by water skiers. Typically, devices manufactured using the vinyl dipping technology of the prior art are notoriously hot, and they stick to the skin. Further, they typically tend to crack around the edges, so they were not only uncomfortable, but they cause abrasion, particularly around the armholes and sides.
Adding to the foregoing problem is that the U.S. Coast Guard Regulations require that the flotation in a PFD be provided by an approved material, and the only presently approved flotation materials are flotation foams. The U.S. Coast Guard has approved the use of Neoprene as a fabric in manufacturing PFDs. Neoprene is a soft, elastic, stretchable, flexible polychloroprene foam material, which can be laminated to a segmented polyurethane known as LYCRA (a synthetic fiber produced by E. I. DuPont de Nemours and Company, located in Wilmington, Del.). While Neoprene, laminated with Lycra, is an approved fabric, neither Neoprene nor Neoprene laminated with LYCRA can be used alone to replace flotation foam. Instead, the laminate is used to enclose an approved foam in a PFD. Other stretch fabrics, such as a spandex omni-directional wrap knit laminated to a monolithic film which is known as DARLEXX (an elastic fabric produced by Darlington Fabrics Corporation, New York, N.Y.), are not approved for use to enclose approved flotation foams in PFDs.
In view of the above, it would be desirable to be able to manufacture PFDs using a U.S. Coast Guard approved flotation material which did not rely upon the enclosure of a flotation foam by an approved fabric material where the fabric material has been stitched to hold individual pieces of foam and which could be molded to various body conforming shapes which enhance comfort, flexibility, mobility, appearance, and/or provide additional body protection from impact. Also, it would be desirable to be able to form such articles in desired shapes and configurations while still providing them with a fabric exterior, rather than with a vinyl exterior or a hardened foam exterior.